Question

Calculate the percent of BaO in 29.0 g of a mixture of BaO and CaO which just reacts with 100.8 mL of 6.00 M HCl.
$BaO+2HCl\to BaC{l}_2+H_{2}O$
$CaO+2HCl\to CaC{l}_2+H_{2}O$

Answer 1

Reactions: $BaO+2HCl⟶BaC{l}_2+H_{2}O$

$CaO+2HCl⟶CaC{l}_2+H_{2}O$

$HCl$ reacted completely

$\Rightarrow \left(0.1008L\right)\times \left(6.00MHCl\right)\times \left(\frac{\text{1 mol oxide}}{\text{2 mol HCl}}\right)$

$\Rightarrow 0.3024$ mol oxides

If the mixture was $100$% $BaO$, $29g$ would contain $\frac{29}{155.32}=0.1891$ mol oxide

If the mixture was $100$% $CaO$, $29g$ would contain $\frac{29}{56.0778}=0.5171$ mol oxide

From unitary method,

$0.1891mol=100$% $BaO$

$0.3024mol=Z$% $BaO$

$0.5171mol=0$% $BaO$

then, $\frac{Z}{100}=\frac{0.5171-0.3024}{0.5171-0.1891}$

$\Rightarrow Z=65.4$% $BaO$